Header positioning for PCB mount

I am designing a PCB which will use the Photon. I don’t want to solder the Photon directly onto the board however. I am planning to use headers instead so I can pop off the Photon or swap out a malfunctioning one easily. What is some material I can use for determining the type of header to use, and the positioning for them on the board (relative to each other as the Photon needs 2 rows of headers)?

Depending on what software you’re planning on using, some models might already be availably. If you search for it on the forums, you should be able to find some. Let us know if you don’t and we’ll see how we can help you out.

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There are eagle parts for the photon in the docs that show the correct spacing

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The datasheet is all the material you need:


But as others have said, if you are using Eagle, all this work has already been done for you in the library linked to in the second section.

Turns out Particle included the headers in their library, and I was able to import these into Eagle pretty easily!

Thanks for pointing out that part of the data sheet indra!

Realized that Particle also provides the model for the Photon itself. Would it be advisable to just use the Photon model instead of the header model? I could just solder headers onto the PCB anyways as they should line up with the pins from the Photon model. This allows me the option of soldering the Photon onto the PCB if I wanted to (I never will), but also guarantees that I don’t mess up the spacing between the two headers. Here’s the current view of the board using the Photon + headers (missing some minor components)

Have a look at how sparkfun make their shields so the photon can be removed (female headers), they even sell them.

i prefer the layout you chose for the photon, with just the single line of holes on each side, while others prefer having the second line for testing and hooking up extras.

Make sure you run a DRC (design rule check) on your PCB, it looks like you have some wires very close and even touching other pads. basically where you see green there will be copper top and bottom so make sure you have clearances around them.

there are some really good tutorials on sparkfun, as well as info on DRC etc. if you send your PCB to a fab house to get them made, make sure you use their DRC as different places have different rules.

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As @Hootie81 pointed out , some of those traces look rather suspect, especially the ones that seem to dead-end randomly or even intersect with other traces (though they might be the same signal). Did you use the autorouter for that layout?

I would just use the Photon part and decide at solder-time whether to use headers or not. We did this with our last batch of boards with the same flexibility in mind. It also makes the layout self-documenting as to the orientation of the Photon, antenna, and USB jack.

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Thanks, that was by no means a completed circuit. Just learning PCB layout tools and sharing my progress :smiley: